1. Technical Field Text
The present invention relates to a method of manufacturing a glass molded product and a lower die for molding glass, and particularly to a method of manufacturing a glass molded product by pressurizing and molding a molten glass droplet with the use of an upper die, an outer frame, and a lower die, and a lower die for molding glass.
2. Background Information
As disclosed in Japanese Laid-Open Patent Publication No. 2008-037703 (PTD 1), a method of manufacturing a glass molded product by pressurizing and molding a molten glass droplet has been known. The glass molded product is used, for example, as an optical element, for a digital camera lens, an optical pickup lens for a digital versatile disc (DVD), a camera lens for a mobile phone, and a coupling lens for optical communication.
Recently, an optical device for which a glass molded product is employed tends to be smaller in size and also higher in performance. Performance required for the glass molded product (for example, shape accuracy) also tends to be higher. Such a glass molded product can be manufactured by pressurizing and molding a molten glass droplet dropped onto a lower die downward from above, with the use of an upper die, an outer frame, and a lower die.
In the method of manufacturing a glass molded product disclosed in Japanese Laid-Open Patent Publication No. 2008-037703 (PTD 1), an outer frame is employed as one of molding dies. In this case, the outer frame is removed from the glass molded product after the pressurizing and molding step. The outer frame may also be used as a part of a component, together with a glass molded product. In this case, the outer frame is not removed from the glass molded product but the outer frame is used for an optical device together with the glass molded product.